Propeller



- July 27 1926.

G. LIPARI PROPELLEB Filed April 22, 1926 2 Sheets-Sheet l ATTORNEY July 27, 1926.

G. LIPARI PROPELLER 1926 2 Sheets-Sheet Filed April 22 INVENTOR Patented July 27, 1 926.

I UNI-TED STATES PATENT A OFFICE.

GAnrANo 1.19am, on SAN JOSE, cALIEoRN'IA.

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Application filed April 22, 1926. Serial R o. 1Q3,901.

- less slip or loss of eflectix e propelling power a that the usual form of propeller, and one that will be exceptionally strongand dursingle unit.

able and-highly efficient in its'practical application.

In the drawing Figure 1 is a front elevation of-my im proved propeller.

Figure 2 is a plan View of the same. Figure 3 is-a perspective illustration of the same.

Referring more particularly to the drawing, I show at 1 the hub portion of the propeller and adapted to engage a driving shaft along its axis of rotation 2 and provided with a plurality of'pairsofoppositely directed and symmetrically arranged blades 'as 3-3, 44 and 5-5.

These pairs of blades are so arranged that their ends'are equally spaced about the circumference of a circlewhcn projected as in Figure 1, or in other words their tips define the apices of the angles of a hexagon. t

The bases of each pair of blades merge into one integral whole, the base of one blade curving around the central hubportion 1 and merging with the base portion of the other blade. This formation is clearly'shown in Figure 2, where the face 6 of one blade 3 is joined to the corresponding oppositely directed face 7 of the other blade 3 by continuing around and over the hub 1 in a torsional curved surface 8, the other two faces of the blades being joined in a similar manner. The blades-44 are'connec-ted in a similar manner asat 11, and the blades 5--5 The base portion of the three ,pairs of blades are formed in one integral whole so that the six blades and their bases form a By'forming each pair of blades as described and arranging the pairs in a regular formation such as hexagonal, the base of each 'air of blades may be caused to merge with, ase of the adjoining pair-of blades.

This is shown at 15, for instance, where the surface -7 of one blade 3 is continued in a torsional curve over the hub portion 1 to merge with the surface of the one blade 4 opposite to the surface 9 and indlcated by the reference numeral 9. Likewise the surface 6 of the one blade 3 merges with the surface 10 of the one blade 4.

The nature of the curved and'connected surfaces 8, 11, 14. 15, 16, l7, l8 isv of vital importance in this invention, these curved surfaces being such that a line drown along their lowest portions from one end of the hub to the other as at 19 would lie almost entirely in the wall of a cylinder havlng'a diameter of the same as the hub 1.

Theseblades may be turned at any suitable angle with'reference to each other, and

spaced as desired. By arranging the blades as described they act successively upon the medium in which'they are caused to operate, the acting surface of each blade being oti'set both longitudinally and laterally from both the preceding and succeeding blades. When a propeller of this formation is in use it offers a negligible resistance to the air or water at the hubpthe resistance being limited to the diameter of the hub itself.

Theoretically it, might be said that the air or water stream is straight at this point as it flows past hub 1, the several blades being enabled to exert their full power upon the air without the disturbing influence of a churning body of air, around the hub.

It is to be understood, of course, that while I have herein shown and described but one specific embodiment of the invention, changes in form construction and method of operation may be made within the scope of the appended claim.

I claim A propeller comprising a hub portion,

and a pluralityof pairs of oppositely directed symmetrically formed blades formed thereon, the blades of each pair being angularly and oppositely directed with respect to ,a vertical plane bisecting them longitudithe oppositely directed surface of the other blade with which it is paired and with the similarly directed surface of" an adjoining blade, the lowest portions of the connecting surfaces passing around the hub stantially cylindrical form.

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